RESUMO
The use of opioids to control cancer pain could be insufficient. Interventional techniques such as a cryoablation have emerged as alternatives to opioids. OBJECTIVES: To summarize the current scientific evidence on the use of cryoablation to control cancer pain. METHODS: A systematic search of the Scopus, PubMed, and Cochrane databases was performed. All articles published before December 31, 2015, whose title or abstract specified cancer pain control as the endpoint were selected. Articles without abstracts and all nonsystematic reviews were excluded. RESULTS: 22 articles were included: 1 randomized clinical trial (RCT), 2 non-RCTs, 1 ambispective study, 9 retrospective studies, 2 nonspecified cohort studies, 3 case series, and 4 case reports. 496 patients with 580 lesions were treated. Lung cancer was the most common primary tumor. 82.8% of the metastases were bone metastases, with or without soft tissue involvement. Cryoablation decreased mean pain scores by 62.5% at 24 hours post-cryoablation, by 70% at 3 months, and by 80.9% at 6 months. Cryoablation was associated with a 44.2% improvement in quality of life after 4 weeks and a 59.6% improvement at 8 weeks. The need for opioids decreased by 75% at 24 hours and by 61.7% at 3 months. Cryoablation in combination with radiotherapy, vertebroplasty, or bisphosphonates appears to be better than cryoablation alone. Complications were highly variable among the studies, but no fatal complications were reported. CONCLUSIONS: Cryoablation is effective in controlling cancer pain without relevant side effects. However, more studies are needed to confirm these results.